1. Field of the Invention
This invention relates to a machine for and a method of hardening the soft ground, which machine is capable of being inserted into or withdrawn from the soft ground in the perpendicular or a predetermined direction during a soft ground hardening operation.
2. Description of the Prior Art
In order to treat the soft ground by a method of hardening the soft ground in depths, a soft ground hardening machine is used, which has an extremely large length and small width. While a deep portion of the soft ground is treated with such an elongated machine, the direction in which the machine is inserted into or withdrawn from the soft ground is liable to be deviated from the perpendicular or a predetermined direction, in which the machine should be moved. This makes it difficult to form a hardened wall in the soft ground in a predetermined manner.
When the direction in which the soft ground hardening machine is inserted into or withdrawn from the soft ground is deviated from a predetermined direction, in which the machine should be moved, the ship from which the machine is suspended is inclined, and the elongated machine is moved forward and backward, and rightward and leftward with an upper portion thereof fixedly held, to thereby eliminate the above-mentioned deviation. According to the above-described method, a high restraining force is applied from the soft ground to the soft ground hardening machine after the machine has been inserted into the soft ground to a certain extent, so that it is difficult to control the direction of the movement of the machine.